Space division multiple access channelization in wireless communication systems

Abstract

Space division multiple access channelization is provided that includes scheduling transmission for two or more terminals and utilizing different code offsets that correspond to different sub-trees. The transmissions can be scheduled on overlapping frequency resources for overlapping time periods on different spatial resources. The pilot code offsets provide different pilot signatures so that the pilot transmissions do not overlap. The overlapping frequency resources can partially overlap or completely overlap.

1. A method for facilitating channelization in a wireless communication system, comprising:
 scheduling transmission to at least two terminals on overlapping frequency resources for an overlapping time period on different spatial resources; and 
 utilizing different code offsets for pilots sent to the at least two terminals, wherein the different code offsets correspond to different sub-trees. 
 
     
     
       2. The method of  claim 1 , wherein the different code offsets create different pilot signatures. 
     
     
       3. The method of  claim 2 , further comprising assigning the pilot signatures to channel sub-trees in a non-contiguous manner. 
     
     
       4. The method of  claim 1 , wherein the number of sub-trees is less than a number of available dimensions. 
     
     
       5. The method of  claim 1 , wherein scheduling comprises scheduling acknowledgement of the transmissions to the at least two terminals on the overlapping frequency resources for the overlapping time period on different spatial resources so that the acknowledgment is transmitted on non-overlapping time or frequency resources. 
     
     
       6. The method of  claim 1 , wherein the overlapping frequency resources partially overlap. 
     
     
       7. The method of  claim 1 , wherein the overlapping frequency resources completely overlap. 
     
     
       8. The method of  claim 1 , further comprising:
 assigning a subset of nodes by eliminating nodes after a node that carries a last acknowledgement segment; and 
 assigning a subset of nodes by removing nodes before the node that carries the last acknowledgement to reduce an assignment size while maintaining the positions of the acknowledgements. 
 
     
     
       9. The method of  claim 1 , wherein the description of subsequent sub-trees is deferred to later overhead channels. 
     
     
       10. A wireless communications apparatus, comprising:
 a processor that executes instructions for scheduling transmission to at least two terminals on overlapping frequency resources for overlapping time periods on different spatial resources, so that pilots transmitted to the at least two terminals utilize different code offsets; and 
 a memory that stores information relate to the instructions executed by the processor. 
 
     
     
       11. The wireless communications apparatus of  claim 10 , wherein the electronic device comprises a scheduler. 
     
     
       12. The wireless communications apparatus of  claim 10 , wherein the electronic device comprises an access point. 
     
     
       13. The wireless communications apparatus of  claim 10 , wherein the different code offsets create different pilot signatures so that the pilots do not collide. 
     
     
       14. The wireless communications apparatus of  claim 10 , wherein the processor is configured to schedule each of the at least two terminals utilizing a different sub-tree of a channel tree. 
     
     
       15. The wireless communications apparatus of  claim 10 , wherein the processor is configured to schedule acknowledgement of the transmissions to the at least two terminals on the overlapping frequency resources for the overlapping time period on different spatial resources, so that the acknowledgment is transmitted on non-overlapping time or frequency resources. 
     
     
       16. The wireless communications apparatus of  claim 10 , wherein the overlapping frequency resources partially overlap. 
     
     
       17. The wireless communications apparatus of  claim 10 , wherein the overlapping frequency resources completely overlap. 
     
     
       18. A wireless communications apparatus that provides space division multiple access channelization, comprising:
 means for scheduling transmission to at least two terminals on overlapping frequency resources for overlapping time periods on different spatial resources; and 
 means for utilizing different code offsets for pilots sent to the at least two terminals, wherein the different code offsets correspond to different sub-trees. 
 
     
     
       19. The wireless communications apparatus of  claim 18 , wherein the means for scheduling comprises means for scheduling each of the at least two terminals utilizing a different sub-tree of a channel tree. 
     
     
       20. The wireless communications apparatus of  claim 18 , wherein scheduling comprises scheduling acknowledgement of the transmissions to the at least two terminals on the overlapping frequency resources for the overlapping time period on different spatial resources so that the acknowledgment is transmitted on non-overlapping time or frequency resources. 
     
     
       21. The wireless communications apparatus of  claim 18 , wherein the pilot signatures are assigned to channel sub-trees in a non-contiguous manner. 
     
     
       22. The wireless communications apparatus of  claim 18 , the number of sub-trees is less than a number of available dimensions. 
     
     
       23. A machine-readable medium having stored thereon machine-executable instructions for:
 scheduling transmission to at least two terminals on overlapping frequency resources for overlapping time periods on different spatial resources; and 
 utilizing different code offsets for pilots sent to the at least two terminals, wherein the different code offsets correspond to different sub-trees. 
 
     
     
       24. An apparatus operable in a wireless communication system, the apparatus comprising:
 a processor configured to:
 schedule transmission to at least two terminals on overlapping frequency resources for overlapping time periods on different spatial resources; and 
 utilize different code offsets for pilots sent to the at least two terminals, wherein the different code offsets correspond to different sub-trees.